Tooth for crushing rolls



Nov. 19, 1929. G. w. WlLMOT TOOTH FOR CRUSHING ROLLS Filed March 26,-1927' INVENTOR A TTORNE Y Patented Nov. 19, 1929 UNITED STATES PATENTOFFICE GEORGE W. WILMOT, OF HAZLETON, PENNSYLVANIA, ASSIGNOB TO WILMOTENGI- NEERING COMPANY, OF HAZLETON, PENNSYLVANIA, A CORPORATION OF PENN-SYLVANIA TOOTH FOR ORUSI-IING ROLLS Application filed March 26,

My invention relates to teeth which are adapted to be mounted upon rollsemployed in crushing and grinding machinery, particularly the rolls ofmachinery employed in the crushing and breaking of coal into commercialsizes.

When coal'is taken from the mine it usually'is in lumps which are toolarge for use in furnaces, stoves and the like; hence it is necessary,before the coal is placed upon the market, that it be broken to reducethe same to sizes required such as are known in commerce as stove, egg,chestnut, etc. The breaking of coal to produce the commercial sizesrequired and desired should be accomplished with the production of assmall a percentage of dust and fine particles as practically may bepossible. The dust and fine particles which may be produced are notsuitable for use in furnaces for heating houses,

stoves and the like, and if used or usable for any purpose must be soldat a smaller price than that which may be obtained for the coal ofcommercial sizes above referred to. Such dust and fine particles,therefore, are in the nature of wastage and production thereof should beavoided if possible.

It therefore is the general object of my invention to provide a tooth ofnovel construction which'is adapted to be embodied in the construct-ionof breaking or crushing rolls and which, when such rolls are employed inthe breaking of coal, effect the breaking thereof with a minimumproduction of dust and relatively small particles.

Also it is an object of the invention to provide a tooth of thecharacter indicated having converging, tapering sides with interposedcutting corners or edges, one of the 40 said corners or edges beingcontinuous and having an apical portion which constitutes the cutting orpenetrating point ofthe tooth while the other corners or edges at theirouter or forward ends terminate on opposite sides of the said apicalportion of the continuous corner or cutting edge.

A further ob'ect of the invention is to provide a tooth o the characterindicated consisting of a body portion having converging,

tapering and concave sides, the corners be- 1927. Serial No. 178,555.

tween the adjoining sides constituting cutting edges and two of thediametrically opposed edges tapering more rapidly toward the outerpointed end of t'he'tooth than the two other diametrically opposed edgeswhereby the outer apical cutting and penetrating edge portion of thelatter is of greater height than the outer end portions of the formerand continues around and constitutes the point of'the tooth and extendsbetween the outer ends of the first named diametrically opposed cuttingedges.

Other objects and advantages of the invention will be pointed out in thedetailed description thereof which follows or will be apparent from suchdescription.

In order that the invention may be readily understood and its practicaladvantages fully appreciated reference should be had to the accompanyingdrawing in which I have illustrated one convenient embodiment of thesaid invention.

It must be understood, however, that the invention is susceptible ofembodiment in other forms of construction than that shown and thatchanges in the details of construction maybe made within the scope ofthe claims without departing from the principle of the said invention. i

In the drawing Fig. -1 is arview in perspective of a tooth embodying theinvention;

Fig. 2 is a view in elevation thereof with a tooth occupying oneselected position;

Fig. 3 isva similar view with a tooth occupyinga position at rightangles to the position in which it is shown in Fig. 2

Fig. 4: is a transverse sectional view taken on the line 44 of 1; and

Figs. 5, 6, 7 and 8 are views showing fragmentary portions. of opposedrolls in longitudinal section upon which teeth embodying the inventionare mounted, the teeth ineach figure being shown as located in differentrelative positions with respect to each other from those in whichtheyare shown in every other of said figures.

In the drawing I have shown a tooth, which is of suitable metal,provided with a shank portion 1 which is adapted to be mounted in a hole2 within a roll 3.

The cutting portion 4 of the tooth preferably is integral with the shankportion 1. If desired the cutting portion 4: of the tooth may beseparated from but connected with the shank 1 by means of a portion 5 ofpoly onal shape in cross section.

The cutting portion 4 of the tooth is generally of pyramidal shape andis provided with four tapered sides 6, 7, 8 and 9 each of which isrendered concave by the presence therein of an oval recess 10 whichtapers from the inner end portion of the tooth to ward the outerpenetrating end thereof as is shown quite clearly in the drawing. Thepresence of the recesses 10 results in the formation of relativelynarrow knife or chlsellike portions 15 at the four corners of thetooth 1. .The lines of intersection of the adjoining sides of thecutting portion 4 of the tooth constitute cutting edges as indicated at16, 17 18 and 19.

The cutting portion 4: of the tooth is so shaped and formed that theedges 16 and 18 thereof toward their outer ends are curved and taperedinwardly or'toward each other more rapidly than the correspondingportions of the edges 17 and 19. The edges 17 and 19 merge into eachother and the outer merging portions thereof constitute an apical curvedcutting portion 20. This portion 1s located intermediate the adjoiningopposed outer ends of the cutting edges 16 and 18. This relationship isclearly shown in the drawing.

As has already been suggested the outer end portions of the cuttingedges 16 and 18 are tapered more rapidly than the corresponding portionsof the cutting edges 17 and 19. The result of this more rapid taperingis that these portions of the edges 16 and 18 are located nearer to thelongitudinal axis of the tooth than are the corresponding portions ofthe cutting edges 17 and 19. As a result of the relationship between theouter portions of the cutting edges thus produced it will be apparentthat inthe use of teeth embodying the invention the apical portion 20will first contact with the object, such as a lump of coal, to bebroken, and will enter the same and will effect cleavage thereof in aplane at right angles to the plane of the cutting edges 16 and 18.Thereafter the lat ter cutting edges operating or cutting independentlywill operate or tend to penetrate and subdivide each of the lumpsproduced by the first cleavage into two lumps, and thereby subdivide theoriginal lump into four lumps or pieces. The average size of thesesubdivided lumps will depend upon the proximity of the teeth to eachother in the coopcrating crushing or breaking rolls.

The teeth may be positioned upon the rolls in an infinite number of waysand relations to each other. In Figs. 5 to 8 inclusive, I have shownfragmentary portions of rolls located in opposed relation to each otherand bearing or supporting groups of teeth, the teeth of each group beingrelated to each other in a manner different from that in which the teethof each other group are related to each other.

In Fig. 5 I have shown the teeth so mounted upon the rolls thatthe'cutting edges 16 and 18 of the teeth on one roll are located inplanes at right angles to the planes of the corresponding cutting edgesof the teeth in the opposing roll. The teeth, as shown in theconstruction illustrated in this figure of the drawing, upon one rollarelocated in alternate or staggered relation with respect to those on theother roll.

In Fig. 6 I have shown the teeth so mounted that when in opposedrelation to each other as shown they are in axial alinement; and theyare also shown as being so mounted that the planes of the respectivecouples of cutting edges 16 and 18 and 17 and 19 of one tooth arearranged at right angles to the planes of the corresponding couples ofthe cutting edges of the tooth in opposing relation thereto.

In Fig. 7 the teeth are so mounted upon the rolls that when in opposedrelation to each other as shown they are in axial alinement, as in Fig.6, but they have each been rotated about their respective axes so thatthe planes of the respective couples of cutting edges of the teeth uponone roll are in the same planes as the corresponding couples of cuttingedges of the teeth upon the other roll. r

In Fig. 8 the teeth upon opposing rolls are shown in alternate orstaggered relation with respect to each other as shown in Fig. 5 butthey have been so rotated about their respec tive axes that the planesof the respective couples of cutting edges thereof occupy differentrelations with respect to each other A from what is shown in Fig. 5.

As already indicated an infinite number of variations in therelationship of the teeth upon opposing rolls withrespect to each othermay be made without departing from the spirit and scope of theinvention.

It may be found that upon operating upon objects of one class orcharacter to subdivide lumps of one size into smaller sizes betterresults may .be obtained if the teeth are mounted in one relation toeach other than if mounted in another. 7

It has been found that by the employment of teeth having theconstruction as illustrated and as described above the production 01dust and small particles is decreased and even though that decrease maybe of a small percentage less than heretofore has been the case, yet inthe aggregate such decrease would result in a saving greatly worthwhile.

Having thus described my invention what I claim and desire to secure byLetters Patent is,

1. A tooth for a crushing roll comprising a body portion having foursides which converge to form the penetrating portion of the tooth, theedges between adjoining sides thereof constituting cutting edges, theouter end portions of two of which edges which occupy positions inopposed relation to each other being more sharply tapered toward theaxis of the tooth than the corresponding portions of the other twooppositely disposed edges, which latter edges merge into each other attheir outer ends at a point which is further from the base of the tooththan the point at which the former of said edges merge with the saidtooth and constitute an advanced penetrating portion of the tooth.

2. A tooth for a crushing roll having tapered convergent sides, theintersection of adjoining sides forming cutting edges which edgesconverge toward the longitudinal axis of the tooth and are curvedinwardly toward the said axis, the outer ends of two of the said cuttingedges located in opposed relation to each other terminating inwardly ofand closer to the base portion of the tooth than the merged outer endportions of the other opposed cutting edges of the said tooth, thelatter constituting an advanced penetrating portion of the tooth.

3. A tooth for a crushing roll comprising a shank and a body portion,the latter being of generally pyramidal shape, the intersections ofadjoining sides forming cutting edges which cutting edges taper from theinner toward the outer penetrating end of the tooth, the tapering of theouter end portions of two of the said cutting edges which are in opposedrelation to each other being more gradual than that of the other cuttingedges of the tooth whereby the former merge into each other at the outerend of the tooth at a point further from the base of the tooth than thepoint at which the latter merge with the said tooth and form an advancedpenetrating portion thereof.

4. A tooth for a crushing roll, which tooth is provided with a pluralityof sides which taper toward the penetrating point thereof, theintersections of adjoining sides of the said tooth forming cutting edgeswhich edges taper from the inner end toward the outer penetrating end ofthe tooth, two of the opposing cutting edges which lie in the same planetapering toward the outer tapering end of the tooth more gradually thanthe other cutting edges of said tooth, and meeting at their outer endsat a point further from the base of the said tooth than the point atwhich the other cutting edges merge with the said tooth, andconstituting an advanced penetrating portion thereof.

5. A tooth for a crushing roll comprising a I shank and a body portionhaving converging, tapering sides, which sides are provided withrecesses therein whereby the said sides are rendered concave and theintersections of the said sides forming cutting edges which taper fromthe inner toward the outer penetrating end of the tooth, two of thecutting edges which occupy the same plane tapering more gradually thanthe other cutting edges of the tooth, and the first named edges mergingat their outer ends at a point further from the base of the said tooththan the point at which the other edges merge with the said tooth toform an advanced cutting edge portion in a plane common to that of theremaining portions thereof, which portion is interposed between theouter ends of the remaining cutting edges of the tooth.

6. A tooth for a crushing roll having converging tapering sides, theintersections of the surfaces of adjoining'sides forming cutting edgeswhich taper from the inner toward the outer penetrating end of thetooth, two of the cutting edges which occupy the same plane taperingmore gradually than the other cutting edge of the tooth, and the saidtwo cutting edges merging at their outer ends at a point further fromthe base of the tooth than the point at which the other edge portionsmerge with the said tooth to form an advanced penetrating edge portionin-a plane common to that of the remaining portions of said edges, whichportion is interposed between the outer ends of the remaining cuttingedges of the tooth.

7. A tooth for a crushing roll, comprising a body portion which isformed with pairs of opposing sides which converge toward the end of thetooth, the sides of each pair of opposing sides converging at equalangles and the intersections of adjoining sides defining cutting edges,the edges of one pair of oppositely disposededges converging toward theaxis of the tooth more sharply than another pair of oppositely disposededges, whereby they terminate inwardly of the outer ends of the saidlast mentioned pair of oppositely disposed edges.

In testimony that I claim the foregoing as my invention I have hereuntosigned my name this 17th day of March A. D. 1927.

GEORGE W. WILMOT.

